Is giving charity on behalf of a deceased parent better and more rewarding than giving charity on behalf of oneself, taking into account that Allah has coupled His worship with honoring one's parents?

Giving charity on behalf of a deceased parent is commendable and is a form of showing kindness and devotion to them after their death, as the Prophet (peace and blessings be upon him) said: "When a person dies, all his deeds come to an end except for three: ongoing charity, beneficial knowledge, or a righteous child who prays for him."

As for preferring charity on behalf of a parent over charity for oneself, this has not been reported from the scholars. In fact, some scholars deemed it disliked to prioritize others in acts of devotion, while Ibn al-Qayyim held it permissible.

It is better for one who gives voluntary charity to intend it for all believing men and women, because it reaches them, and nothing is diminished from the reward of the one giving charity.

Regarding the ruling on prioritizing others in acts of devotion: If the act of devotion is obligatory, then it is not permissible to prioritize others in it. However, if it is supererogatory, then it is preferable not to prioritize others, unless there is a benefit in doing so, such as if the father is in the second row and the son in the first, and there is a fear that the father might be upset.

Muslims have agreed on the permissibility and commendability of giving charity on behalf of the deceased, and that its reward reaches them, benefiting them and also benefiting the one who gives the charity.